Symmastia is a condition where the breasts appear to merge across the midline of the chest, eliminating the natural cleavage. Instead of a distinct separation, a continuous mound of tissue, fat, or skin connects the breasts over the sternum. This anatomical variation can be present from birth or develop later in life.
Understanding Symmastia
Symmastia is characterized by the absence of a defined intermammary cleft, the space that typically separates the breasts. Visually, the breasts appear as one continuous unit across the sternum, sometimes described as a “uniboob.” The severity varies, from a less noticeable lack of cleavage to a complete fusion of breast tissue. The underlying issue involves skin and breast tissue detaching or failing to adhere to the breastbone, allowing the breasts to meet in the center.
Normally, the skin between the breasts is securely attached to the midline of the chest wall, creating a clear separation. Muscle fibers further contribute to maintaining this division. With symmastia, this natural anatomical separation is compromised, leading to breasts appearing too close together with minimal or no space.
Common Causes
Symmastia can arise from two origins: congenital or acquired. Congenital symmastia is a rare condition present from birth, resulting from developmental anomalies where breast tissue inherently merges across the midline. Its exact causes are not fully understood, but it is thought to involve a genetic element and abnormal collagen arrangement.
Acquired symmastia, also known as iatrogenic symmastia, is more common and typically develops as a complication following breast augmentation or reconstruction surgery. This form can occur immediately or gradually over time. Several surgical factors contribute, including overly aggressive or wide dissection of breast pockets near the sternum. This can weaken natural structures, allowing implants to shift inward, potentially causing discomfort or outward nipple rotation.
Other contributing factors include breast implants that are excessively large for the patient’s chest frame. Implants that are too wide exert pressure on central chest muscles and skin, causing them to loosen and connect. Improper placement, especially too close to the midline, also increases risk. Placing implants over the pectoral muscle rather than underneath it may increase risk by offering less protection against merging. Inadequate anchoring of implants or a narrow sternum can also predispose an individual to symmastia.
Correction Options
Correcting symmastia primarily involves surgical intervention to restore natural cleavage and improve appearance. The approach depends on symmastia type, severity, and implant involvement.
One method involves temporarily removing breast implants, if present, to access and close the opening between pockets. Surgeons often adjust implant shape and size to better fit proportions and redefine cleavage. Capsulorrhaphy, tightening the implant capsule with internal sutures, secures implants within designated pockets and limits medial movement. This creates an “internal bra” for support.
Excess fat or tissue from the sternum area may be removed via liposuction or surgical resection to deepen cleavage. Fat grafting can also refine contours and address tissue deficiencies. For congenital symmastia, correction often involves liposuction of the intermammary region, followed by suturing skin to the underlying sternum to establish separation. Postoperative compression garments support healing and maintain the newly created cleavage.